yea, they've been doing that for at least a year, and it does look better. but unfortunately, they can't deal with sites in some colors, so if you're running a background of anything other than white or grey, you're kind of screwed. After going around and around on that with them, they told me they have no plans to fix it.
I dunno, I first noticed them last summer on a halloween site. (also on a black background) The thumbnails look great, the rest of the page, not so much. They're also using them with the custom search now.